Submarine signaling



E. E. TURNER, JR

' SUBMARINE f-IGNALING April 23, 1946.

Filed April 1, 1941 INVENTOR v EDwaN E. TURNER,JR. WM

ATTORNEY Patented Apr. 23, 1946 ATENT OFFICE SUBMARINE SIGNALING EdwinE.- Turner, Jr., West Roxbury, Mass., as signor toSubmarine SignalCompany, Boston, Mass, a corporation of Maine Application April 1, 1941,Serial No. 386,311

12 Claims.

The present invention relates to the mounting and installation ofsubmarine signaling apparatus on a vessel.

One of the greatest obstacles in the way of clear reception of submarinesound signals is extraneous noises in the vicinity of the receivingapparatus which for the most part raises the noise to signal ratio sothat good reception is made difficult. This difficulty is observed inboth sound ranging in which a directed high frequency sound beam is senttowards an object which reflects a reflected impulse and in thedirective listening wherein a sound signal or noise is picked up by thelistening vessel from some other vessel in the vicinity whereby thevessels direction is determined.

In order to determine direction of an oncoming sound Wave, particularlyin the higher frequency ranges, that is at or above the limit ofaudibility,

the installation must be such that the sound passes to the pickup unitswithout being altered in direction. It is obvious that if theinstallation on mounting is such that the sound pattern of the receiveris changed from its normal form, or if the sound pattern is-so distortedthat the receiver no longer possesses its directive qualities, or if thesound is dispersed so that its direction at the receiver is noindication of the direction of. the sound source, it follows that thereceiver or pickup units will not function properly to determinedirection of the sound or the direction of the reflecting sound source.

For lower frequencies tank-mounted installations within a vessel haveproven in many cases to be satisfactory. However, such installations arenot as sensitive as installations externally of the vessel and deeperdown in the water and for higher frequencies for various reasons,reception becomes generally poorer for this type of installation. As analternative or perhaps an improvement upon tank-mounted installationwithin the vessel, particularly at high frequencies, it has been acommon practice to project the soundprojecting or receiving unit whichusually has directive qualities of reception, below the vessel from asea chest and to rotate the sound receiver or sound projector fromwithin the vessel. These devices have been made spherical in shape inorder to decrease the water noise, particularly the noise created by thevessel moving through the water. However, considerable noise may stillbe created because of the projecting shaft and various other elements inthe unit itself. In order to overcome these efiects I have created anentirely new type of installation which has a great number of advantagesboth in its construction and in its utility of operation.

In the present invention the unit is mounted externally of the vesseland joined to the vessel along a peripheral surface, When the apparatusis to be used for sound reception, the housing externally of the vesselis inflated by fluid means which may be the same liquid through'whichthe soundis propagated which is pumped into the enclosure formed by theflexible housing attached to the vessel and the vessel. The housing,when inflated, preferably is made to assume a shape whereby when thevessel is in motion, water will flow past it with a minimum of waternoise. The shape should also be such that a positive pressure is builtup at the front part of the unit well around towards the sides so thatit is desirable under these conditions not to create pressure-releasesurfaces until towards the rear portion of the structure. Thesound-projecting or pickup units are operative entirely within theexpanding yielding enclosure, preferably in the portion towards thefront, in a quiet medium in which it may be rotated or directed in thedesired direction. The casing of the yielding cover is preferably madeof a sound-transparent or substantially sound-transparent material sothat the compressional waves approaching from any direction to the unitwill not be interfered with or reflected as it passes through the wallof the unit. The unit preferably extends longitudinally with the keel ofthe vessel and, if desired, the receiving unit within the casing may beshielded from the ships propeller noises or from noises approaching fromother sectors of the vessel. Shielding may be provided not only from theship's propeller sounds but also from sounds transmitted through thehull by using shielding means in various portions within the section ofthe skin of the vessel partitioned off by the clamping unit. In additionto this, the clamping unit holding the yielding casing to the skin ofthe vessel may be of such size and mass that noises approaching to thehousing so formed by the ring will be reflected back in the skin fromthe direction from which they came.

The present invention also provides a distinct advantage in that whenthe sound pickup units are wholly withdrawn within the vessel, the

yielding cover or casing may be sucked up against the skin of thevessel, thereby permitting the vessel to proceed in the water withoutresistance and also permitting the vessel to be drydocked for repairswithout the danger of the unit or even the casing itself being harmed.

The invention will be more fully described in connection with thedrawing in which Fig. 1 shows a mid-vertical section of the device asinstalled in the vessel, Fig. 2 shows a plan view as viewed from thebottom of Fig. l; and Fig. 3 shows a fragmentary section of the viewshown in Fig. l.

In Fig. 1 the skin of the vessel is represented as I. To this. on asuitable flat portion of the vessel in the vicinity of the keel, isbuilt up a large fairing plate 2 which may be of the order of 15 to 20feet long and 4 to 8 feet wide. This fairing plate is welded or rivetedto the skin I to form a substantially smooth and continuous surface withthe skin. The plate 2 is provided with a recess or groove 3 extending ina continnous curve in its flat surface which, in conjunction with asimilar recess 5 in the top clamping member 4, provides a cavity tocontain and grip the yielding housing 6. The groove or recess 3 in thefairing plate 2 is of an oval shape and similarly also with the recessin the clamping plate 4. The clamping plate I. however, is provided witha shoulder 8 parallel with the surface of the fairing plate 2, whichshoulder gradually is curved backwards at the surface 9 against whichthe yielding cover or housing'B may rest. The yielding casing or housing6 is preferably made of a uniform extensible material such as gumrubber, or similar compounds, and may before inflation lie flat againstthe ship's skin within the clamped area, but, if desired, the unit maybe made of a canvas or somewhat similar type fabric which issubstantially yielding and flexible or semi-flexible, but notsubstantially extensible, in which case the housing 6 must besubstantially shaped to conform to the desired shape of the housing orcasing when in use. When a flat sheet of rubber is used, the peripheraledges may be reinforced under the clamping region with fabric or cord soas to confine the extensibility of the material beyond the clampingsurfaces. The casing 6, when inflated by means of the pump III, whichmay use the external water medium through the connection II and thevalve I2, is extended by the pressure which is set up within the housingI3 to a form somewhat like that shown in Fig. 1, which is substantiallysimilar to one-half ellipse of revolution with the front end a littlelarger but of substantially the same sharpness or pointedness as in therear end. The sound-propagating or pickup unit I4 is projected into themedium or space I3 of the housing by means of the shaft I5 extendingthrough the sea chest I6 in the usual manner. The unit is positionedforward of the center so that a substantial forward angle of 180 ormore, as defined by lines from the unit to the housing, contain thehousing surface on which only positive pressure is built up by themotion of the vessel in the water and is held in place against upwardpressure within the housing by suitable means not shown. The unit I Imay be rotated by any well-known means by rotation of the shaft I5 sothat it can be used to pick up sounds approaching in any direction. Whenthe unit is not in use, the shaft I5 is raised and the unit I4 withdrawninto the housing I6. The liquid in the space I 3 may then be sucked inthrough the pump I0, in which position the skin will be held against theskin I of the vessel. In this construction the sound approaching fromdirections forward and to the side of the vessel will penetrate withoutdistortion into the medium in the space I3 and will be received by theunit I 4 without any distortion. Under this condition whateverdirectional qualities are given to the unit I4, they may be utilizedfully and completely without interruption in determining the directionof the sound source. The casing or cover 6 may. if desired, be removedwhen the vessel is docked by taking out or loosening the clamping screwsI I and then pulling out the entire cover. The shape and size of thecover 6 are determined to some degree by the conditions under which thedevice is to be used. If only forward directions are desired, theforward portion of the unit may be made blunter and deeper than the rearportions of the unit, but if it is desired to build up pressure forbetter reception along towards the after portion of the unit, the unitwill be less blunt and more uniform. On the whole, however, it will bedesirable to place the receiving or projecting unit slightly forward ofthe center portion of the unit, as in this case a greater receivingdirection can be maintained.

It may be desirable also to change somewhat the shape of the unit withthe speed and characteristics of the vessel, but on the whole these willnot vary greatly from the shape described above.

Having now described my invention, I claim:

1. In combination with a vessel, an external mounting for submarinesignaling means comprising a flexible yielding skin forming an elongatedbody extending substantially parallel with the normal forwardsmotion ofthe vessel and approximately streamlined, means for inflating said bodywith a sound-propagating medium, and submarine signaling means adaptedto be positioned therein.

2. In combination with a vessel, an external mounting for submarinesignaling means comprising a flexible yielding skin, means clamping theskin at its edges to the bottom of the vessel. means for inflating saidskin with a sound-propagating medium and forming an elongated bodyextending substantially parallel with the forward motion of the vessel,said body being approximately streamlined, and submarine signaling meansadapted to be positioned therein.

3. In combination with a vessel, an external mounting for submarinesignaling means comprising a flat flexible extensible yielding skinhaving it periphery attached to the skin of the vessel, means forinflating the skin to form an elongated substantially streamlined bodyextending in the direction forward and aft of the vessel, and submarinesignaling means adapted to be positioned within said inflated body.

4. In combination with a vessel, an external mounting for submarinesignaling means comprising an extensible flexible yielding skin havingits edges attached to the surface of the vessel, means for inflatingsaid skin to form with the surface of the vessel a body of substantiallyelongated oval shape, and submarine-signaling means adapted to bepositioned within said elongated body.

5. In combination with a vessel, an external mounting for submarinesignaling means comprising an extensible flexible yielding skin havingits edges attached to the surface of the vessel, means for inflatingsaid skin to form with the surface of the vessel a body of substantiallyelongated oval shape, and submarine signaling means adapted to bepositioned within said elongated body, said submarine signaling meansbeing positioned forward of the central section of said body.

6. In combination with a vessel, an external mounting for submarinesignaling mean comprising an extensible flexible yielding skin havingits edges attached to the surface of the vessel, means for inflatingsaid skin to form with the surface of the vessel a body of substantiallyelongated oval shape, and submarine signaling means adapted to bepositioned within said elongated body, said submarine signaling meansbeing positioned within said body whereby the forward 180 section formedwith the submarine signaling means as a vertex includes portions of thesurface of said body which is substantially at all times under positivepressure,

'7. In combination with a vessel, an external mounting for submarinesignaling means comtached to the skin of the vessel, said body beingapproximately 15 feet or more long and 4 to 8 feet in width, means forinflating said body with a sound-propagating medium, and submarinesignaling means adapted to be positioned within the vessel and extendedinto the medium within said body.

9. In combination with a vessel, an external mounting for submarinesignaling means comprising a flexible yielding skin forming an elongatedbody of substantially semi-oval form attached to the skin of the vessel,said body being approximately 15 feet or more long and 4 to 8 feet inwidth, means for inflating said body with a sound-propagating medium,and submarine signaling means adapted to be positioned within the vesseland extended into the medium within said body, said submarine signalingmeans adapted to be rotated and having directional properties wherebythe position of said means corresponds to a given direction of the soundsource.

10. In combination with a vessel, an external mounting for submarinesignaling means comprising a flexible yielding skin forming an elongatedbody of substantially semi-oval form attached to the skin of the vessel,said body being approximately 15 feet or more long and 4 to 8 feet inwidth, means for inflating said body with a sound-propagating medium,and submarine signaling means adapted to be positioned within the vesseland extended into the medium within said body, said submarine signalingmeans being directive and means for rotating the same to determine thedirection of the incoming sound waves.

11. In combination with a vessel, an external mounting for submarinesignaling means comprising an extensibleflexible yielding skin havingits edges attached to the surface of the vessel, means for inflatingsaid skin to form with the surface of the vessel a body of substantiallyelongated oval shape, and submarine signaling means adapted to bepositioned within said elongated body, and acoustic insulating meansadapted to be positioned in the rear of said submarine signaling meansto shield the same against noises arriving at the'submarine signalingmeans.

12. In combination with a vessel, an external mounting for submarinesignaling, means comprising a flexible yielding skin forming anelongated body extending substantially parallel with the normal forwardmotion of the vessel and approximately streamlined, means for inflatingsaid body with a sound-propagating medium, and means for withdrawingsaid inflating medium and holding said body flat against the skin of thevessel.

EDWIN E. TURNER, JR.

